Offset printing machine



May 8. 1928.

A. FALLOT OFFSET PRINTING MACHINE Filed Feb. 1. 1924 2 Shets-Shec 1 Izzoezz for ,4 b'//0r y v I May 8, 1928. 1,668,999

A. FALLOT OFFSET PRINTING momma Filed Feb. 1. 1924 2 Sheets-Sheet? a iii/9T2 Jlw elder H. Fa//of 5 feeding side of the machine. This organizathree cylinder off-set Patented May 8,. 1928.

Amman FALLOT, or PLAUEN,

oFFmEQ GERMANY; HARRY PBIESTER EXECUTOR 0F SAID ALFRED JIFALLOT, DECEASED.

orrsn'r rnmrmc mcmnn Application filed February 1, 1924, Serial No. 890,030, and in Germany February 14, 1923.

This invention relates to improvements in printing machines in which the off-set cylinder is provided with a blanket on one half in the ordinary way whilst the other half of the circumference acts as a transporting surface to deliver the sheet printed side up to the delivery tapes. In the present machines of this type the direction of rotation of the plate and off-set cylinders is such that the inked plate cylinder surface, before it contacts with the offset surface or blanket is only visible and accessible on the side of the machine remote from the operator who is stationed at the tion and arrangement of the machine parts prevents the operator from inspecting the plate and if necessary wiping it by hand be-- fore the transfer or inking operation-onto the offset surface. Y

According'to this invention the oif-set-and plate cylinders, preferably both of the same diameter, rotate in such a direction that the inked plate passes in view of the operator at the front or feeding end of the machine in moving from the inking rollers to the point where is transfers or inks on to the off-set f Q blanket, whilst the sheets .are fed by an auxselected as best suited for machine reorganized as iliary feeding arm to the front side of, the impression cylinder. By this arrangement the sheet is printed when moving upwardlyinstead of downwardl By making the plate cylinder of the same diameter as the combined off-set and delivering cylinder,

more space is provided for inspection and hand wipingpf-theplate. .The sheets-are delivered, to" the tapes arranged in amannerwhich is v the three cylinder off-set print-in above describe and. for the purpose set I s v Inj the drawings Figure 1 shows'a three cylinder 'oif-set p slim w i cor n to this invention in. sideelevation. v 2 7 Figure 2 is a side elevation illustratmgthe workinfig of thje' tdeliv'erytapes which 'Iprefer Figure 2 a na -tsetsereamed arrangement of thesuction and blowing holes in the blanket-cylinderas well of a valve arrangement adapted to cooperate with thesame.

i direction inwhich the sheet moves. printed side, up,

:ylinder,

parts of the printing 7 more room for inspection and wiping. The

direction of rotation of these cylinders is indicated in Figure lby arrows, from which it will be seen that the plate, after it has been in contact with the roller of the ink ing mechanism e passes downwardly to the front of the machine where the plate can be seen and if necessary wiped by the attendant, who stands at the right hand side of the machine in Figure 1.

The cylinder 11 has two surfaces a and a.

The surface a is covered with rubber which acts as a. blanket ortransfer. Between the two faces a? and a grippers are accommodated in the cylinder a and, are adapted to take up the sheet after rinting and to pass it over' to the sheet dehverer, The face an of the off-set cylinder may have suction holes h through which the sheet is sucked on to the cylinder to be delivered on to a system of conveyor tapes 5 moving in the spine is delivery may be effected by breaking the suction and placing the holes in'commumcation witha source of compressed air. Such mech:

anisms are well known and need not be here in fully describedor illustrated.

The sheet fed to the impression cylin-i der '6 by means of an auxiliary gripper d and'is carried downwards in F1 1. 1

being seized by suitab e grippers e'rein. 'Under the off-set and impression or printing cylinders, a system of tapes is arranged as hereinafter described and is dethis 'signed to take" the printed sheet of. the combined transfer and delivering cylinder a and to convey the same to the pile directly below the plate cylinder 0 (Figs. 1 and 2).

The machine is driven-in anyconveuient Lil manner as by a belt and transmission wheels 0, n, p indicated in the drawings. To stop the printing the eccentric bearings of the cylinder a are oscillated in the well known manner so asto remove this cylinder from its contact with the plate and impression cylinders. One half of the plate cylinder 0 is fitted with a device for mounting the plate, the other half being ground with a plain smooth surface.

The inking mechanism e is arranged above the plate cylinder in such a manner that the inking rollers are in contact with the eylins der, the damping mechanism f of usual construction being arranged below the plate cylinder 0. The damping mechanism serves as will be known to damp or moisten the plate cylinder 0 before each inking process in order to prevent the entire surface of the plate being covered with ink. Between the damping mechanism f and the inking mechanism e, a considerable space is left free on the cylinder and at this point the state of the surface of the plate cylinder may be readily observed and the surface dampened by hand, if required, prior to inking. An inking by hand may become necessary when the machine is started and the prepared part of the plate cylinderis situated between the damping and the inking mechanisms so that it can. not be damped by themechanism f before being inked. A damping by hand, or the like by means of a wet sponge, may also become necessary when an inspection of the machine shows that the mechanism f is operating unsatisfactorily.

The general operation will be readily understood from the above description. The sheet fed to the impression cylinder 1) by the auxiliary grippers d is printed at one revolution of the cylinder 1) by its contacting with the rubber blanket of the cylinder a and at the next revolution of the cylinder 1), the grippers mounted on the blanket cylinder a take the sheet over from' the impression c linder b and carry it round to the sheet de ivery tapes. The vacuum, which acts through the holes h sucks the sheet on to the'cylinder a during this operation. At the moment of delivering the sheet on to the tapes, thefvacuum is displaced by compressed air whereby the sheet is delivered on to the tapes '5, which are moving in the same direction and speed as the sheet, that is from left to right in Fig.1. The toothed wheel 11 operates by means of the gears p and o the toothed wheel 0 of the cylinder a. From the gear 0 the movement is transmitted to the shaftof the pulleys k by means of the gear k and an intermediate gear 7:2 which latter is arranged in the shaft 8. This device is clearlyshown in Fig. 4. From this figureit will also be seen that when the pulleys k are operated, the tapes operated by the same will be by the blades g.

moved in the same direction and with the same velocity as the wheel 0, the cylinder a and the sheet upon the same.

The surface of the combined blanket and delivery cylinder a may be grooved and in front of this cylinder, blades 9 may be arranged directly opposite and in register with these grooves so as to peel or strip the sheet sheet in the opposite direction and deliver I it on to the pile.

The first mentioned group of tapes, guided over the pulleys i and is, move in the same direction and at the same speed as the printed sheet carried by the gripper of the cylinder a. These'tapes take up the sheet which has been stripped off the cylinder 0.

As soon as the sheet is placed on'the tapes which pass over the pulleys z' and is,

these pulleys, which are mounted on levers,

are swung around the axes s and s so as to lower the tapes whereby the sheet is transferred on to a second set of tapes, WlllCh are guided over the pulleys j, m, l,- and 9' and which at the time of the transfer areactually at rest. The sheet which has come to rest inthis manner is delivered by this second set of tapes to thepile. The pulleys j and j are stationary, whilst the pulleys Z and m are transportable with the rack z and are moved forward and backward by the crank m and the transmission gear wheels 7 and a, of which the wheel 1' gears with the stationary rack 32 Whilst the wheel 7& gears with the transporting rack z. The rack z is shown in full lines in its eirtreme position to the. left in the figures when a sheet has been placed on the pile. When the rack .2 is moving towards the delivery pile, the pulleys l and m are secured against rotation by pawls, whereby the tapes with the printing sheet thereon are moved from under the cylinder (i' to a position over the dc,-

livery pile and the pulleys j and 7' during 7 in the figures, that is from the position,

shown in full lines to that shown in dotted lines, the pulleys m and Z are carried along known and the details may be varied withcylinder a is carried round from the printing to the delivery position without any danger of altering its position on the cylinder, owing to the action of the vacuum. Slur-ring of the printed surface is, thus prevented. As soon as the gripper on the oil'- set cylinder a brings the front edge of the sheet over the conveyor tapes 2', it, the grippers release the sheet and air under pres sure is admitted to whatjwere suction holes till they pass the point, where they lie directly over the conveyor. The rear part of the sheet continues to be held by the other rows of suction holes. compressed air, the sheetis uniformly deposited on the conveyor tapes and is pushed on by the action of the suction holes which have not yet reached the vacuum breaking position. The sheet is therefore properly laid on the conveyor tapes without any danger of slur-ring as the sheet is not moved on the surface of the cylinder and if the blades 9 are not'used any friction of the sheet on these blades is also excluded.

Thesuction and blowing holes are arranged in successive rows upon the circumference of the cyllnder. For the holes a valve device is arranged at the end of the cylinder in a manner which will be evident to those skilled in the art. A constructional form of an advantageous arrangement is shown in section in Fig. 2*. According to this arrangement a. suction conduit k and a pressure conduit 7L2 are connected to a plant adapted to supply suction and pressure. Such plants willalways be at hand in greater printing ofiices. The shaft of the'cylinder a is equipped with a channel k8 which by means of radial channels is interconnected with the series of holes in the periphery of the cylinder. When this cylinder a is rotating the holes 72. are by means of the radial channels alternately brought into connection with the section conduit h and with the pressure conduit 71. (or with the atmosphere). Such control valves are known per so. A single valve This pneumatic transmission of the sheet by the combined off-set and delivering cylinder a is of great importance 1n the execution of high class printing work.

I claim:

1. In a three cylinder off-set rotary print-' in machine, a combined off-set and delivery cy inder,. a plate cylinder, means for rotat- By this action of the ing the off-set and plate cylinder in such a direction that the inked plate passes in view of the operator at the front or feeding side of the machine in moving from the inking rollers to the point where it transfers or inks on to the off-set blanket, and an auxiliary-gripper for feeding the sheets to the front side of the impression cylinder.

2. In a three cylinder off-set rotary print-- ing machine, a combined off-set and delivery cylinder, a plate cylinder of the same diameter as the said off-set cylinder, means for rotating the off-set and plate cylinders in such a direction that the inked plate passes in view of the operator at the front or feeding side of the machine in moving from the inking rollers to the point where it transfers or inks on to the off-set blanket and an auxiliary gripper for feeding the sheets to the front side of the impregsion cylinder.

3. In a three cylinder off-set rotary printing machine, a combined off-set and delivery cylinder, a plate cylinder of the same diameter as the said off-set cylinder, means for rotating the off-set and plate cylinders in such a direction,-that the inked plate passes in view of the operator at the front or feeding side ofthe machine in moving from the inking rollers to the point where it transfers or inks on to the off-set blanket, an auxiliary gripper for feeding the sheets to the front side of the impression cylinder, holes on the combined off-set and delivery cylinder, on the transporting surface thereof, and means in connect-ion withsaid holes for applying suction therethrough to the said holes, in

inder of half the diameter of the combined off-set ,and delivery cylinder and an auxiliary gripper for feeding the sheets to the front side of the said impression cylinder.

5. In a three cylinder off-set rotary print- .ing machine, a combined off-set and delivery cylinder, a plate cylinder of the same diam eter as the offset-cylinder, said off-set and plate cylinders rotating in such a direction that the inked plate passes n view of the operator at the front or feeding side of the machine in moving from the inking rollers to the point where it transfersor inks on to the off-set blanket, an impression cylinder. of half the diameter of the combined off-set and delivery cylinder, an auxlliary gripper for feeding the sheets to the front side of the said impression cylinder, holes in the transporting surface of the combined off-set and delivery'cylinder, means adapted to 1pply-suction through the said holes to the sheet in order to retain the same Without :"the. operator at the front or .feeding.,side of the machine in moving from the inking rollers to the point where it transfers or inks on to the oil-set blanket an impression. cyl- *inder, an'auxiliary gripper for feeding the .sheets to the front side of the said impression cylinder, grooves in the said combined ofi-set and delivery cylinder, stripping-off blades, arranged adjacent to the surface of' said combined ofi-setand delivery cylinder and 'two groups of conveyor tapes, said stripping" ofl' blades peeling. off the sheets from the combined oil-set and delivering cylinder and delivering the same in a flat uncriinpled state to one group of conveyor tapesmoving in the same direction as the sheets .and delivering'the sheets to the second group of conveyor tapes which moves in the opposite direction and delivers the sheets to the pile.

In testimony whereof I aflix, my signature.

ALFRED FALLOT. 

